I understand why BYOD is not provided for a second line that was created from a cloned line: it would be too easy to use such a line in a permanent second location. But what is the reasoning behind disabling Simul Ring for the second line?

With a second line, my wife and I can each have our own number. It would be nice if each of us could have that number ring a cell phone in order take calls while out of the house. I can do that now through forwarding, but Simul Ring is so much more convenient.